Vacuum pump



Dec. 28 1926. 1,612,287

F. E. HOLMES VACUUM PUMP Filed Sept. 17, 1925 2 Sheets-Sheet l Dec. 28 1926. 1,612,287

F. E. HoLMl-:s

VACUUM PUMP Filed Sept. 17, 1925 2 Sheets-5119?, 2

Affare/@yr Patented Dec. 28, 1926.

UNITED STATES 1,612,287 PATENT OFFICE.

FRANK E. HOLMES, OF PASADENA, CALIFORNIA, ASSIGNOR T0 BLOOMFIELD-HOLMES. CORPORATION, OFPASADENA, CALIFORNIA, A, CORPORATION OF CALIFORNIA..

VACUUM PUMP.

Application filed September My invention relates to vacuuln pumps, and 1t particularly concerns a vacuum pump which is very suitable for use in pumping wet vacuum.

At the present time there is no pump which is of a design which makes it entirely satisfactory for Wet vacuum use; for example, in filter plants and the like a vacuum pump is used. A Water trap is placed in the vacuum line which extends from the filter to the vacuum pump. Sometimes this trap does not catch all of the Water, and slugs of water reach the pump entering the cylinder. It is necessary to Work the plston and the cylinder head of the pump at very close distances so that eiiciency may be obtained. This Water entering the cylinder is not readily expelled therefrom and being' in-4 compressible causes a loosening or breakage of the piston head when the piston approaches this head. Such an occurrence as this necessitates a repairing of the vacuum pump which inqmost cases retards production of the apparatus on which such pumps are used.

It is an object of my invention to provide a vacuum pump which is adapted for use on systems having Wet vacuums.l My pump is so designed that in the event any Water should enter the cylinders thereof, this Water Will be quickly expelled.

It is also an object of my invention to provide an exhaust valve arrangement Which assists in the ready expelling of Water from the cylinder of the pump.

It is another object of my invention to provide a quick acting exhaust valve.

It is another objectof the invention to provide an exhaust valve of the character mentioned Whose action is not affected by centrifugal force. I accomplish this object by providing a certain design of valve which is placed in a radial plane. This will be described later on.

It is also an object of my invention to provide an exhaust valve which may be readily removed from place.

It is another object of my invention to provide a simple and sturdy vacuum pump. The pump of my invention comprises three main moving parts.

It is another object of this invention to provide a vacuum pump which is adapted to be directly connected to a driving source such as a motor. This is a considerable provide a vacuum pump 17, 1925. Serial No. 56,860.

saving as it eliminates all interconnecting mechanisms. l

Another object of my invention is to provide a vacuum pump which is adapted to `run at high speed.

It is also an object of my invention to provide a vacuum pump of this character in which the piston stroke may be regulated.

It is still further object of my invention to of the character mentioned in which the plston moves into intimate proximity of the head of the pump, thus making an eiiicient vacuum pump.

It is an additional object of my invention to provide a novel form of intake valve which is removable.

Other objects and the salient advantages of my invention will be specified hereinafter. Referring to the two sheets of drawings 1n which I illustrate a preferred form of mv invention,

Fig. 1 is a plan view of an apparatus employlng a vacuum pump of my invention.

F 1g. 2 is an enlarged View of my invention sectioned to illustrate the details thereof.

Fig. 3 is a fragmentar sectional view taken on the line 3-3 of ig. 2.

.Fig 4 is a perspective detail showing a piston of my invention and clearly showing the removability feature of the intake valve of my invention.

Fig. 5'\is a perspective view showing a semi-cylindrical member and a septum plate of my invention having my novel form of exhaust valve.

Fig. 6 is an enlarged fragmentar sectional view taken on the line 6 6 of idg. 5- showing in detail the construction of the exhaust valve of my invention.

lVith reference especially to Fig. 2 my invention provides a ump 11 which is composed of semi-cylintrical members 12 and- 13 and a septum plate 14. The semi-cylindrical member 12 has a semi-cylindrical chamber 16 formed on an axis B--B as shown in Figs. 2 and 5, and the semi-cylindrical member 13 has a semi-cylindrical chamber 17 which is formed on an axis A-A`, as shown clearly'in Fig. 5. The Ine-mbers 12 and 13 are secured together with the septum plate 14 secured therebetween by screws 19 which extend through flanges 20, as shown clearly in Figs. 1 and 2. As shown in Fig. 5 these members l2 and 13 are so secured that the axes A-A and B-B extend at lright angles to each other and intersect each other. A pivot'bar 22 is formed on the septum plate 14 inside the chamber 16, this pivot bar 22 extending concentrically along -of the intake valve members 60 an the axis B-B. A pivot bar 23 is formed on the septum plate v14 in the chamber 17, this pivot bar 23 extending concentrically along the axis A-A.

As shown clearly in Figs. 5 and 6, 4the septum plate 14 is rectangular and has the corners thereof cut away providing diagonal faces 25. By cutting away the corners of the septum plate 14, the .chambers 16 and 17 are communicated with the exterior of the pump 11 as clearly shown either in Fig. 5.or Fig. 6, thus the chambers 16 and 17 are provided with exhaust ports 26. Web portions-27 of valve members 28 are placed against the diagonal faces 25. Securing bars 30 having curved side faces 31 are provided to clamp the valve members 28 in place, there being screws 29 acting directly against these bars 30 to secure the bars in place. Valve portions 33 and 34 extend from the web 27 and close the ports 26 of the chambers 16 and 17. From Fig. 5 it is quite obvious that the valve members 28 are placed in a position as far'as possible from the center of the pump; that is, farthestfrom the point of the intersection of the axes A-A and B-B and extend in a radlal plane.

A'piston 40 is situated in the chamber 16y and a piston 41 is situated in the chamber 17 The pistons 40 and 41 have semi-cylindrical faces 42 which engage liners 43 in the chambers 16 and v17 and have radial faces 44 which are separated by bearing channels 45. Intake ports 47 connect between the radial faces 44 and intake chambers 48. The intake chambers 48 are connected by a passage 49 with an intake passage 50. The pas sage 50 of the piston 40 extends througn ay shaft 51 Awhich is formed integral therewith, this shaft 51 extending from the piston 40 through openings 52 and 53 in the liner 43 and the member 12. The passage 504 of the iston 41 connects with a passage 54 formed in a shaft 55. The shaft 55'is secured inside a cylindrical projection 56 of the iston 41 by suitable 'set screws-57, as clear y shown in Fig. 2. A suitable stuffing box 58 may be provided around the shaft 55 for providing a tight seal between this shaft 55 and the cylindrical projection 56.

Central portions 59 of intake valve mem* bers 60 rest in thel bearing lportions 45 and are retained in place byv bushings `61 as clearly shown in Fig. 2 and in Fig. 4. Dowel pins 62 extend from the pistons projecting through openings 63 in the central ortions extend through openings 64 in the bushing members. The dowels 62 serve to position the intake valve members 60 and the bushings lfinitesimal size` an 61. As shown in Fig. 2 inner faces 65 of. the bushings 61 engage the pivot bars 22 and 23 swinging therearound and serving as bearings for the pistons 40 and 41. Extending froni the central portions 59 of intake valves 60 are valve portions 68. These valve portions 68 extend along the radial faces 44 and extend so as to close the ports 47, as shown clearly in Figs. 2 and 3.

With reference to Fig. l the shaft 51 extending from the piston 40 extends through a bearing 70 which is secured to a base 71. On the extending end of the shaft 51 is placed a stuffing box 72 from which there extends a pipe "73. The shaft 55 connected to the piston 41 extends through a motor 75 and has a stutling box 76 placed on the extending end thereof f roni which there extends a pipe 77. rl`he motor is secured to a pivoted base 78 which is swung by means of a worm 79 which engages rack teeth of the base T8. The worin 79 is operated by a wheel 8l which is secured on a shaft 82 which The operation of my vacuum ,pump-may be understood by considering lthe action of a common type of universal joint. The pistons 40 and 41 and the housing of the pump 11 operate in substantially the `same. manner as the three main parts of'a universal joint. It will be noted in Fig. 1 that the shafts 51 and 55 are out. of alignment. There will, therefore, be a relative movement of the three main parts of my invention when the shafts and the pump rotate. With reference to Fig. 2 it will be noted that the pistons 40 and 41 are of less cylindrical extension than the chambers 16 or 17, and there is therefore a sector shaped cavity 86 formed in each of the chambers 16 or 17. During a rotation of the pump the piston 40 swings from a position shown in Fig. 2 into such a position that the upper radial face 44 comes into closeyassociation with a face 87 of the .septum plate 14, and then returns to the position shown in Fig. 2. Vhen the upper radial face 44 is in adjacency with the face 87, the,

lower radial face 44 is in its farthest position from the face 87, and there is formed a faces. Therefore, during one revolution of the pump, the cavit 86 decreases to an in- -then increases to its largest size. Also during a revolution of the pump a cavity at the lower part of the piston 40 increases from an infinitesimal size to amaximum size and then decreases again in size.

Vhen the cavity 86 is decreasing in size, the valve portions 34 of the valves 28 are moved into the position indicated by the `dotted line 88 of Fig. 6 by the pressure of the air in the cavity 86, which air is exhausted.

.As the cavity 86 increases in size, the valve the cavity SG'at these places. The intake valve portion 68 in this cavity 86 1s at this time removed from engagement with the radial face 44 and opens the ports 47. The enlarging of the cavity 86 creates a suction which draws gas or fluid theremto through these ports 47. Then the cavity has reached its largest size and the piston 40 begms a return stroke, the mentioned valve portion 68 closes and the valve 'portions 34 open and repeat the operation just described. The operation of both of the pistons and 41 and the operation in all of the cavitles is the same, but they operate out of phase, and as one is decreasing in size, another is increasing in size as is obvious from an mspectionof the drawings.

The pipes 7 3 and 77 are connected to the apparatus on which a vacuum is to be placed. The stroke of the pistons 40 and 41 1s 1n proportion to the angularity of the shafts 51 and 55. This angularity may be varied by operating the wheel 81 which rotates the movable base 78 by means of the worm and rack engagement. alignment there will be no relative motion between the parts of my pump, and there will be no pumping action or power con sumption. The intake valve members 60, by reason of my novel construction, are re placeable and when they become inefficient may be readil replaced by new valve members so that t e eiciency of the pump may be maintained.

The exhaust valves 28 as clearly shown in Fig. 5, are placed at the corners of the chambers 16 and 17. Should any liquid, failing to be caught by a liquid trap, pass into the chambers 16 or 17, it will be thrown to the corners of these chambers by centrifugal force. Therefore, when the cavity 86 decreases in size, the water will be forced from the chambers 16, or 17 upon the initial decreasing of the cavity. For this reason the presence of Water slugswill not interfere with the operation of my vacuum pump and the pump will not be damaged thereby, as sometimes occurs in other vacuum pumps. By placing the valve portions 38 and 34 of the exhaust valves 28 in radial planes, there will be no centrifugal action thereon which would interfere with their operation. The portions and 34 are very light and are quick acting because there is very small inertia to be overcome. This is very desirable as the eiiiciency of a vacuum pump depends very much on the quick action of the valves thereof.

It will he noted in Fig. 6l that the side walls 31 of the bars 3() are curved. These walls are curved so that there will be no sharp corners for the valve portions 33 or 84 to swing on. These valve portions are swung on the curved face and all of the bending will not occur at one point.- In

When the shafts are in to move so that the radial faces 44 approach very closely to the faces 87 -of the septum plate 14. This also contributes to the elficiency of my vacuum pump. It is obvious and well known that any air left in a chaxnber of a pump expands on the intake stroke of the pump and reduces the efficiency thereof according to the amount of air left in the chamber or cylinder.

The feature of varying the stroke of the pistons 40 and 41.1nakes it possible to start the pump at a low load and then increase the load to the desired degree. This is accomplished by swinging the shaft 55 into alignment with the shaft 51 so that there will be no movement of the pistons 40 and 41 in the chambers 16 and 17 As the pump gains its normal speed, the shaft 55 may be gradually swung into the desired position.

I claim as my invention: i

1. In a .device of the class described, the combination of: a body having a semi-cylindrical chamber; a piston in said chamber said piston being swingable on the axis o said semi-cylindrical chamber, said pistonY having a suction port; a replaceablel suction valve for closing said suction port; and replaceable exhaust valves secured at the corners of said body.

2. In a. device f the class described, the combination of: a 'pair of semi-cylindrical members having semi-cylindrical chambers secured together in such a manner thatthe axes of said chambers intersect and extend at right angles to each other; a septum plate secured between said chambers.; pivot bars less danger i f' carried by said septum plate in said semicylindricalchambers, said pivot bars extending on the axes of the chambers in which they are disposed; pistons swingable in said semi-cylindrical chambers, said pistons being semi-cylindrical and of less cylindrical extension than' said semi-cylindrical chambers, said piston swinging on said pivot bars, there being intake ports -connecting with radial faces of said pistons; intake valvey members associated with each of-said pistons, said valve members having valve portions for closing said intake ports, said valve members being secured in place between said pistons and saidpivot bars;` and exhaust valves for said semi-cylindrical chambers.

3. In a device of the class described, the combination of: a semi-cylindrical member;

a septum plate secured to said scmi-cylin- 1 drical member, thus providing a closed chamber of semi-cylindrical cross section; a pivot bar in said chamber, said pivot bar extending concentrically of the axis of said chamber; a piston in said chamber, said piston being of a semi-cylindrical cross section of less cylindrical extension than said chamber, said piston having a pair of radial faces in which intake ports are formed, there being a bearing portion formed between said 'radial faces; a valve member having a eentral portion resting in said bearing portion and valve portions for covering said intake ports; a bushing for engaging said central portion and holding said valve member in place, said bushing engaging said pivot bar; and an exhaust valve for said chamber.

4. In a device of the class described, the combination of: a semi-cylindrical member; a septum plate secured to said semi-cylindrical member forming a semi-eylindrical chamber; a piston operable in said chamber, said piston having an intake passage; an intake valve for closing said intake passage; and an exhaust valve for closing an exhaust passage of said chamber, said exhaust valve being mounted on a radial plane.

5. In a device of the class described, the combination of: a semi-cylindri Ial member; a septum plate secured to said semi-cylindrical member forming a semi-cylimlrical chamber; a piston operable in said chamber, said piston having an intake passage; an intake valve for closing said intake passage; and an exhaust valve for closing an exhaust. passage ot' said chamber, said exhau t valve being mounted to open and clos-e in a plane parallel to the axis of rotation of said member so that it will not be ai'eeted by centrifugal force.

6. In a device of the class described, the combination of: a semi-cylindrical member; a septum plate secured to said semi-cylindrical member forming a semi-cylindrical chamber; a piston operable in said chamber; said piston having an intake passage; an intake valve for closing said intake passage; and an exhaustvalve for closing an exhaust passage of said chamber, said exhaust valve being mounted at the farthest position from .the center of rotation of said Chamber.

7. In a device of the class described, the combination of: a pair of semi-cylindrical members secured together, said members having semi-cylindrical chambers; a septum plate secured between said members, said plate being rectangular in shape and having a corner cut away to provide exhaust ports for said chambers; an exhaust valve closure secured to said plate in such a manner that valve portions thereof close said exhaust ports; and pistons operable in said chamlzers, said pistons having intake means for said clian'ibers.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 12th da;v of September, 1925.

vFRANK E. HOLMES. 

